During his appearance on the late-night talk show, Damon told host David Letterman that last week he received two giant baskets of fruits from Fey and Poehler. The two comedians additionally attached two letters. One letter was an apology from them for hurting his feelings with their jokes at the award show, in which they called him "garbage man."

The other letter read, "If your note is part of some George Clooney prank, as I very strongly suspect it is, you A-list amateurs are going to have to step it the f*** up. We are not some easily confused starlets here. We are grown-a**, professional comedians. Please accept this fruit as a token of our sincerity. Best wishes, Elizabeth Tina Fey, Amy 'Boston' Poehler."

The star of "The Bourne Ultimatum" then realized that Clooney had sent a "wounded letter" to the comedians on stationery with his name on it. "I have no idea how many letters are out there, to how many people," he added.

Clooney, meanwhile, opened up about the recent prank involving "The Monuments Men" co-star in an interview with SiriusXM. "I've already started the ball rolling. I used Matt, sorry," Clooney said of his revenge.

"I sent her a letter saying, 'Dear Tina, listen, it's from Matt,' " Clooney said with a laugh. "And it just says, 'Look, it sounds hypocritical because I laughed at the jokes about George and Leo, but you know, that's sort of what people think about them. But when you called me a garbage man, it just seemed like low hanging fruit, it just seemed like an easy joke. And you know, I don't want an apology, I don't want anything else, I just want you to know that my kid now calls me the garbage man.' "

Clooney then added that his mission would not stop right there. "She said step it up. That's the appetizer and what's coming now, the main course, is pretty brutal," Clooney revealed, adding that he already prepared the next prank. "This one is one that I have it in my hotel room set - taking pictures and stuff - I'm sitting there like, 'If I do this, this is downright dirty.' I have to think if I'm actually going to do it or not."